Article: Adalimumab

Adalimumab (Humira®) is the third TNF antagonist (after infliximab and etanercept) to be approved in the US. Like infliximab and etanercept, adalimumab binds to TNFα, preventing it from activating TNF receptors; adalimumab was constructed from a fully human monoclonal antibody, while infliximab is a mouse-human chimeric antibody and etanercept is a TNF receptor-IgG fusion protein. TNFα inactivation has proven to be important in downregulating the inflammatory reactions associated with autoimmune diseases. As of Jan 2006, adalimumab has been approved for the treatment of rheumatoid arthritis and psoriatic arthritis, and data have been submitted to the FDA for expanding the label to include the treatment of plaque psoriasis. Other possible indications are likely to include those in which infliximab or etanercept have already been tested in and/or approved for, including ankylosing spondylitis and Crohn's disease.

Humira is marketed in preloaded 0.8 ml syringes and is injected subcutaneously, typically by the patient at home. It cannot be administered orally, because the digestive system would destroy the drug.

Humira's manufacturer is Abbott Laboratories.

Lawsuit

In March 2003, British company Cambridge Antibody Technology (CAT), stated its wish to "initiate discussions regarding the applicability of the royalty offset provisions for Humira" Abbott Laboratories in the High Court of London. In November 2004, the trial began. In December 2004, the Judge, Justice Laddie Ruled for CAT stating "Abbott was in error when it made its first royalty payment to CAT calculated on the basis that only 2% of the Net Sales was due. It should have calculated on the basis of the full royalty of just over 5% and should have paid and continued to pay CAT accordingly." Abbott later paid CAT $23.7 million.

Safety

According to the product labeling of infliximab, etanercept, and adalimumab, these drugs are in the class of immunosuppressants. After a number of studies and reports of adverse reactions in patients receiving anti-TNF alpha therapy (including serious and sometimes fatal blood disorders, infections, rare reports of lymphoma and solid tissue cancers, rare reports of serious liver injury, and rare reports of demyelinating central nervous system disorders), the U.S. Food and Drug Administration issued a warning to doctors appearing in the respective product labeling of these drugs instructing them to screen and monitor potential patients more carefully

Similar agents

• Infliximab
• Etanercept